Dual ignition system



Jan. 9, 1945. I R. F. HORTON 2,367,023

DUAL IGNITION SYSTEM Filed Dec. 11, 1943 2 SheetS -Sheet 2 3 HBMIIIIIQIHP E Q J v v 5 /IIIlIIlIIII|-7HH I INVENTOR;

A A TTOENEY son.

Patented Jan. 9, 1945 UNITED STATES PATENT I OFFICE I DUAL SYSTEM v 7 Roger FgHorton, Hempstead, N. Y.

Application December 11, 1943. Serial No. 513,883

10 Claims.

My invention relates to ignition systems for internal combustion engines and more particularly to improvements in dual ignition systems.

It has long been recognized that, particularly in larger internal combustion engines, improved ignition of the fuel charge is obtained if two spark-plugs are employed in eachcylinder. Both of these plugs may be supplied with ourrent from the same ignition system, but in cer tain cases it has beenfound preferable to use separatesystems, .the chief advantage of which is that in the event of failure of one of the systems, the other'will continue to function and hence at least one of the plugs ineach cylinder will fire. Dual ignition systems of this type are used where reliability vin the operation of the engine is of great importance, such as in aircraft engines.

However, with dual ignition systems of this type, it is difiicult to properly time the two systems with respect to each other so that plugs in any one cylinder fire at the same instant. Ifone plug fires ahead of the other, there is little or no improvement in combustion over tha obtained from a single spark-plug.

One of the objects of my invention is to provide a dual ignition system so interconnected that both oftthe spark-plugs fire inunison; even though the timers of the respective ssytems are not perfectly timed with respect to each other. Another. advantage of my improved system is that, should one of the ignition systems fail, the

other will supply current to both of the plugs,

whereby both plugs. will continue to fire in uni- Further objects and advantages of my invention will be apparent from the following description considered in connection with the accompanying drawings which form a part of this specification and of which;

Fig. l-is a schematic wiring diagram of one embodiment of my invention; and

Fig. 2 is a similar wiring diagram of another embodiment of my invention. 1 v In the following description and in the drawingsonly three pairs of spark-plugs have been shown and described for the sake of simplicity, inasmuch as it will be perfectly obvious how additional pairs would be connected .in the systems.; Like elements in the separate ignition systems making up the dual system of each embodiment have been given like reference characters, but with the suffixes ,a and b, respectively. v i

Referring more particularly to Fig. 1, refer-- ence character Illa. designates a suitable source of direct current, such as the usual three-cell,

six-volt storage battery, one side of which is grounded at 12a. The other side of the storage battery is connected through an ignition switch Ila with a timer shown schematically and designatedby reference character Ilia. The timer includes a breaker arm l8a carrying a-contact point a which is repeatedly open and closed with respect to a fixed contact point 22a by means of a cam 24a, there being a condenser 23a connected across the points.' The cam is driven through suitable timing gears from the crankshaft of the internal combustion engine and is so timed or adjusted as to open the contacts whenever it'is desiredv that any one of the I plugs should fire. Contact 22a is connected to tacts338a, 40a, 42a, 44a, 46a andlfla are provided.

Each cylinder of the internal combustion engine is provided with a pair of spark-plugs, and

., one plug of each pair is connected by a suitable conductor with a fixed contact of the distributor.36a. As above stated, for the sake of simplicity only three pairs of spark-plugs are illustrated, those connected to the distributor 38a beingdesignated by reference characters Ella,

52a andila.

The contact point 34a of the distributor is ro tated through suitable timing gears by the crankshaft of the engine and is so timed that it is in contact with one of the fixed points whenever a spark is desired atthe plug which is connected Moreover, the timer and distributor are so timed'with respect to each other, that the point 34a is in contact with one ofthe fixed points whenever the circuit is broken through-the timer 16a.

, The spark-plugs 50b, 52b and 54b are connected' toasimilar ignition circuit including the distributor 36b and a timer Nib, both driven through suitabletiming gears from the crankshaft. The two distributors and'the two timers are so timedwith respect to each other, as to op erate in synchronism, insofar as this is possible. However, it isrdimcult to so adjust the timers plug 50a. Inasmuch as the interconnection is systems, the second timer to opn determines the instant at which both plugs will fire, 'as'was the case in Fig. 1. Both plugs will continue to fire even though the battery, timer and/ or distributor of one system 'fails; Inasmuch as there is a separate induction coil for eachsparkplug, one or more of these could fail without seriously impairing the operation of the engine.

While I have shown and described several more :supplying high tension current to one spark-plug of each pair, a'separate electric circuit for supplying high tension current to' the other sparkplug oi each pair, and conductor means for interconnecting said circuits so that each circuit may supply current to the spark-plugs of the other circuit.

2. In a dual ignition system for'an internal combustion engine, a pair of spark-plugs for each cylinder of said engine, an electric circuit including a. first timer for supplying timed high tension current impulses to one spark-plug of each pair, a separate electric circuit including a second timer for supplying timed high tension current impulses to the other spark-plug of each pair, and conductor means interconnecting said circuits at points between the timers and the spark-plugs of the respective circuits.

3. In a dual ignition system for an internal 7 between the low tension sides of the two ignition combustion engine, a pair of spark-plugs for each cylinder of said engine, an electric circuit including a timer, an induction coil and a distributor for supplying timed high tension current impulses to one spark-plug of each pair, a similar electric circuit for supplying timed high tension current impulsesfto theotherplug of each utor for supplying timed high tension current impulses to one spark-plug of each pair, a similar electric circuit for supplying timed high tension current impulses to the other plug of each pair, and means interconnecting the spark-plugs of each pair.

5. In a dual ignition system for an internal combustion engine, a pair of spark-plugs for each cylinder of said engine, an individua ignition circuit for supplying high tension current to the diflerent plugs of said pairs, each circuit including an induction coil dividing the circuit into a low tension portion and a high tension portion. and means for interconnecting the low tension portions of said circuits.

6. In a dual ignition system for an internal combustion'engine, a pair of spark-plugs for each cylinder of said engine; an individual ignition circuit for supplying high tension current to the diiierent plugs of said pairs, each circuitincluding a, timer, a distributor connected to receive low tension current from said timer and a separate induction coil between each spark-plug and said distributor, and means interconnecting the circuits so that each circuit may supply current to the spark-plugs of the other circuit.

'7. In a dual ignition system for an internal combustion engine, a pair of spark-plugs for each cylinder of said engine, an individual ignition circuit for supplying high tension current to the different plugsof said pairs, each circuit including a timer, a distributor connected to receive low tension current from said timer and a separate induction coil between each spark plug and said distributor, and means interconnecting said circuits at points between the timers and the spark-plugs of the respective circuits.

8. In a .dual ignition system for an internal combustion engine, a pair of spark-plugs for each cylinder of said engine, an individual ignition circuit for supplying high tension current to the difierent plugs of said pairs, each circuit including a timer, a distributor connected to receive low tension current from said timer and a sepa rate induction coil between each spark-plug and said distributor, and means interconnecting said circuits at points between the distributors and the'spark-plugs of the respective circuits.

'9. In a dual ignition system for an internal combustion engine, a pair of spark-plugs for each cylinder of said engine, anindividual ignition circuitfor supplying hightension current to the different plugs of said pairs, each circuit including a timer, a distributor connected to receive low tension current from said timer and a separate induction coil between each spark-plugand said distributor, and means'interconnecting said circuits at points between the distributors and the induction .coilsof the res ective circuits.

a 10. In a dual ignition system for an internal combustion engine, a pair of spark-plugs for each cylinder of said engine, an individual ignition circuit for supplying high tension current to the different plugs of said pairs, said circuit including a timer, a distributor connected to receive low tension currentfrom said timer, an induction coil connected to each plug and a conductor connecting each coil to the distributor, conductor means connected between the conductors of the 'difierent circuits which" supply current to the ROGER HORTON.

Patented Jan. 9, 1945 Victor -F. 1Hribar, -.Chicago, Ill., assignor to American Lumber-8t Treating 00., a corporation of Delaware N Drawing. Application July 10, 1942,

Serial No. 450,493

6 .Claims.

I use.

"The most troublesome'impuri'ty is the increase in the so-called. coke residue and matter insoluble in benzol. Most of the coke and benzol insolubles are forms of carbon,'although'asmall amount may be dirt, wood fibre, resins, etc. The

impurities are classified as insoluble'A', insoluble B and insoluble C. They are due to the use of pressure. temperature, the presence of wood resins, moisture, oxygen, etc., encountered. 'under} normal impregnation schedules. The American Wood-preservers Association specification and other treating standards limit the coke residue and benzol insoluble because these may interfere with good creosote treatment.

.For instance, the AWPA specification-"for grade 1 creosote (Manual Standard 47) states: It shall not contain more than 0.5% of 'matterinsoluble in benzol but it carries the following footnote, Samples of creosote-taken from working tanks may show an increase in matter insoluble in benzol due to treating operations. Such increases provided'they do not exceed by 1% the specification limits should not serve to cause rejection of the creosote for non-conformity with specifications if it can be shown that the original fresh oil was" of specified quality. The foregoing evidences the change; however, once past the 1% tolerance it is necessary to clean the creosote.

The term cleaning creosote is used in the industry to'mean theremoval of carbon and other insolubles. I

In general, more weight is given to the benzol insoluble test than the coke residue test.

Creosote is a distillate of coal-tar produced by high temperature carbonization of bituminous coal; it consists principally of liquid and solid aromatic hydrocarbons and contains appreciable naphthalene, anthracene, and many others. It

is evident that creosote is closely associated with carbon and other complex compounds.

At the present time the common methods to remove coke residue and benzol insoluble are-by filter press or centrifuge; 1

The data in the AWPA Proceedings show that creosote with a 1.35 per cent benzol may be filtered to a 0.81 per cent benzol insoluble or centrifuged to a 0.56 percent benzol insoluble. It has-been further shown that certain of the benzol insolubles'are also water soluble and may or may not be fully removed by present cleaning methods. Y 1 I Both the filter press and the centrifuge have certain disadvantages. The centrifuge handles only small volumes of creosote and must be attended almost constantly. The filter press is a verydirty operation and it requires practically, a water-free creosote which is difficult to obtain.

Both processes are comparatively'e'xpensive.

The fact is wellknown that part of the creosote fractions known as the benzol insoluble will settle if; permitted to stand Without agitation. This accounts for sludge in storage and'working tank bottoms; however, this rarely accomplishes sufficient benzol insoluble removal to be considered as creosote cleaning.

It has now been discovered that materials used in the mining industry as depressants in connection with water solutions of ore may likewise be employed to produce more rapid and complete precipitation of carbon and other insolubles from creosote to such an extent that inexpensive and thoroughly satisfactory cleaning of the creosote may be accomplished with small percentages of the depressants.

The depressants used in the mining industry comprise a rather wide class including alkali metal cyanides or other soluble cyanides, zinc sulphate, sodium phosphite, starch and the alkali metal dichromates.

pyridines,. acridines, benzene, toluene, xylene,

In the treatment of creosote these materia may be employed, but potassium permanganate, starch and potassium dichromate have been found particularly useful.

Starting with dirty creosote with a 3.00 per cent benzol insoluble, it was found that by the addition of '1 per cent potassium permanganate. or 1 per cent starch (by weight), the matter insoluble in benzol after settling for 1 week was 0.66 and 0.78 per cent, respectively, while the control settled to only 2.55 per cent.

A possible theoretical explanation for the greater amount of sludge that was found to be 

